This invention relates to a brick-forming vacuum press, and more particularly to such a press which is equipped with flexible sealing means.
An earlier brick-forming vacuum press was disclosed by the present assignee in Japanese patent application No. 58161/1971, filed Aug. 2, 1971. In the ensuing years, further developments and improvements have been made, and presses of this nature have found wider commercial utility year after year.
A brick-forming vacuum press is generally constructed of a die and top and bottom plungers disposed along the same vertical central axis. The die is located between the plungers so that a mix placed in the die will be compressed by means of the top and bottom plungers. To facilitate charging of the mix into the die and discharging of a resulting product from the die, the die and the plungers are vertically movable relative to each other.
In apparatus of this nature, it is extremely important to maintain a vacuum in the space defined by the die and plungers. On this subject, the present assignee filed Japanese Utility Model Application No. 185870/1981 on Dec. 14, 1981, disclosing a vacuum chamber which utilizes a flexible skirt element. An attribute of such a skirt is that it permits a greater expansion/contraction stroke along the central vertical axis of the press.
The apparatus disclosed in this specification is particularly advantageous because, in addition to providing effective sealing and permitting greater strokes of the press elements, it provides a superior production efficiency.
According to this invention, it is possible to maintain a degree of vacuum which has been difficult to achieve in prior art presses. The invention permits full automization of a high performance brick forming vacuum press which successively performs the functions of charging a mix into the die, pressing the mix between the top and bottom plungers in a vacuum, and removing the resulting compact. This is done without substantial interruption and without the attendance of any operators or workers. The operational reliability is extremely high, and there are significant improvement in production efficiency.